Thomas midgley. He invented CFCs to replace the previously most commonly used refrigerants: Sulfur Dioxide and Ammonia which are both pretty nasty and should have been replaced… just not with CFCs. Leaded gasoline was invented to help prevent knocking and increase fuel efficiency. Today we use other additives and are better able to reform low octane hydrocarbons into higher octane ones with modern catalysts. Then as another commentater mentioned, he contracted Polio later in life and invented a sling and pulley system to help him out of bed.